Aspheric lenses can be beneficial for those who struggle driving in the dark, working on a computer, and even for sports players that require fast focus. An aspheric lens is not spherical. Instead, these lenses have a flat edge in comparison to a curved edge in spherical lenses. The flat edge prevents spherical aberrations (distortions) and allows for a sharper image.
What are Aspheric Lenses?
Aspheric lenses have a peripheral flat edge that allows light rays to be focussed by the eye. The flatter edge contains a power that is lower than the center. This reduces distortions and allows for clear vision. These lenses are a bit more complex than spherical lenses and are higher in cost. Although they have a flat edge, aspheric lenses still sit comfortably on the eye.
How are Aspheric Lenses Commonly Used?
Aspheric lenses are used to improve peripheral vision, to see in low light situations such as driving at night, for certain sports, and for presbyopic patients. For patients who wear high-plus lenses, these lenses offer less magnification. They also provide minification for those who wear high minus lenses. Although available for astigmatic and presbyopic patients, these lenses are available only for low amounts.
What is the Main Difference Between Aspheric Lenses and Non-Aspheric Lenses?
Spherical lenses are the most commonly worn lenses that consist of a curved front surface. Aspheric lenses are similar to spherical lenses except in that they have a flat peripheral edge. Because of the optical structure of spherical lenses, the curved edges cause spherical aberrations. These aberrations or distortions occur because the light rays fall at different points. However, the eye is unable to focus all the rays, resulting in a blurry image. The flat periphery of the aspheric lens allows the light rays to all come together at one point. This allows the eye to focus on the light rays and create a sharp image.
How Do You Know if You Need Aspheric Lenses?
If you have a large pupil, have had cataract surgery, have high hyperopia or myopia with low astigmatism, are a presbyope, or struggle to see at night, Aspheric lenses may be the best option for you! Although aspheric lenses are great for various things, some conditions are not recommended for aspheric lens use. These include but are not limited to keratoconus or LASIK-corrected eyes.
Where Can You Get Aspheric Lenses?
Aspheric Lenses can be ordered by your local optometrist, or here after you have been fitted with the correct lens for you and your prescription. Most presbyopic lenses have an aspheric surface.
What Are Some of the Best Brands for Aspheric Lenses?
Aqualens 55 Aspheric and Aqualite 55 Pro Aspheric are two lenses that are offered through Contacts Compare. The Aqualite 55 Aspheric lens design effectively controls spherical aberrations in the lens and human eye. As described above, spherical aberrations are the inability of your lens to focus light to a common point. However, because of the curvature of these lenses, the Aqualite 55 Aspheric and Pro Aspheric contact lenses can focus light, providing clearer, crisper, sharper vision regardless of the amount of correction required. At the same time, a thinner, patented edge design provides excellent comfort. Aqualite 55 Aspheric provides better vision, comfort, and proven performance. Both are an economical option and sell at $41.99 for a 3-month supply (single eye).
Furthermore, Coopervision carries an array of aspheric lenses of different material and water content ratios. These different ratios provide different levels of comfort and vision for the patient. These lenses also offer UV blocking. These lenses begin at $59.99 for a 3-month supply (single eye).
The Avaira lenses are silicone hydrogel lenses with a Dk/t of 110. This provides wearers with extreme comfort and increased oxygen flow. These are available for purchase in powers +8.00D to -12.00D.
Cooper Biofinity, Biofnity XR, and Biofinity Energys
Cooper Biofnities are made of silicone hydrogel and have the highest Dk/t of all cooper lenses. The Dk/t of 160 provides wearers with high oxygen transport and extreme comfort. Biofinity and Biofinity Energys lenses are available in powers +8.00D to -12.00D. Biofinity XR is available in +8.50 to +15.00D and -12.50D to -20.00D. All of these lenses can be daily wear or extended wear with monthly replacements.
Cooper MyDay and MyDay toric
The MyDay lenses are silicone hydrogel lenses with a Dk/t of 100. These provide high oxygen transport and optimum comfort. They are available in powers of +8.00D to -12.00D.
MyDay toric lenses also silicone hydrogel have a Dk/t of 80 meaning they have slightly lower optimal comfort compared to the spherical MyDay lenses. However, they are offered in a larger range of powers from plano to -6.00D with cylindrical or astigmatism powers of -0.75, -1.25, and -1.75, -6.50D to -10.00D with cylinders in -2.25 and -0.75, -1.25 and -1.75, +0.50 to +6.00D with cylinder -2.25 and +0.25 to +6.00D with cylinder -0.75, -1.25 and -1.75.
The clariti 1-day and clariti 1-day multifocal lenses are made of silicone hydrogel and have a Dk/t of 86 proving them to be the most comfortable of the clariti lenses. These are followed by the clariti 1-day toric with a modulus of 57. Clariti 1 days are available from -0.50D to -10.00D and +0.50D to +8.00D. Clariti 1-day torics are available from plano to -6.00D and -6.50D to -9.00D and +0.25D to +4.00D in cyl powers of -0.75, -1.25, and -1.75. The multifocal lenses can be purchased in powers of +6.00D to -8.00D.
The proclear 1-day lenses, made of silicone hydrogel, provide spherical powers from +8.00D to -12.00D. They are daily disposable lenses with a Dk/t of 25 meaning that a low amount of oxygen can pass through the lenses and may not provide the optimum comfort.
The proclear multifocal lenses do not have aspheric optics but they do have a center aspherical design that still provides some decreased aberrations. Its features include visibility tint and a low modulus. A low modulus allows flexibility of the lens for optimal comfort. These lenses are available from +6.00D to -10.00D spherical power. They are daily lenses that are purchased as a 90-pack. For more information on multifocal lenses, check out our article about bifocal and multifocal lenses.
The Biomedics 55 by CooperVision allow both myopic (nearsighted) and hyperopic (farsighted) correction. These lenses are available in +0.25D to +8.00D and -0.25 to -10.00D. These lenses have a low dk/t of 28.1 meaning that a low amount of oxygen can pass through the lenses. These lenses may not provide the optimum comfort for most wearers.
Aspheric lenses are an excellent option for those who struggle to see in the dark, who work on a computer, or patients who are sports players. However, they are not recommended for those who have keratoconus or LASIK-corrected eyes.
The most comfortable aspherical optics seem to be the CooperVision Biofinity family with a Dk/t of 160. These also have a wide variety of choices from Biofinity, XR, and Energys providing you with the greatest chance of finding the perfect lens.
Visit your local Optometrist to discuss the best contact lens options for you!